Research On The Type System Of XML Database | Posted on:2005-09-17 | Degree:Master | Type:Thesis | Country:China | Candidate:D Liu | Full Text:PDF | GTID:2168360152969178 | Subject:Computer software and theory | Abstract/Summary: | PDF Full Text Request | With the increasing demand of various web applications, XML database technology has become an important research area of advanced database technologies. The research of the type system of the XML database is a key field of researching XML database system. According to the current research status of XML type processing problems, we will investigate the type validation and type checking problems for the type systems of the XML Database deeply.We first proposes a basic formal model for the XML type system using a particular logical formalism modeling technic based on type thoery, which can realizes the function of type defining and type validating of XML data. After that the basic model is well extended to satisfy XQuery typechecking requirement.For the type validation problem, we compare and analysis several methods to deal with this kind of problem, especially focus on the method based on tree automatons, and propose a modification for the algorithm used by such a method..For the type-checking problem, we first discuss the two particular applications, the one during the XML publication of relational database, and the one during the XML transformation. Then we discussed the decidability of both problems when using XML Schema to present the type on the base of the research of such kind of problems when using DTD to present the type. We point out only with the constrains of the publishing or transformation of the XML, the type-cheking problem is decidable and algorithms can be available when using XML Schema instead of DTD to present the type.Finally we propose the design of the type processing system of XML database XDM and realize it based on the algorithms already introduced.
| Keywords/Search Tags: | XML Database, Type System, Logical Formalism Modeling, Type Validation, Type-Checking | PDF Full Text Request | Related items |
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